What stocks to invest in
One of the initial topics in my first investment course in graduate school was beta, a measure of the relationship ( generated from a regression analysis) between the price changes of an individual stock and those of the market. A stock with a beta of 1.1, for example, tends to move in the same direction as the market but 10% more strongly. One with a beta of 0.9 tends to move in the same direction as the market but 10% less strongly. The beta of a stock portfolio is the weighted average of the betas of its constituents.
the beta of gold stocks
At the end of the class, the teacher posed a question that would be the first item for discussion the following week. Gold stocks have a beta of 0. What does that mean?
The mechanical, but wrong answer, is that gold stocks lower the beta, and therefore the riskiness, of the entire portfolio. If I have two tech stocks, their combined beta may be 1.2. For two utility stocks, the beta might be 0.8. For all four in equal amounts, then, the beta is 1.0, the beta of the market. Take two tech stocks and add two gold stocks and the beta for the group is 0.6. But this doesn’t mean the result is a super-defensive portfolio.
A beta of 0 doesn’t mean the stock is riskless. It means that the stock returns are uncorrelated with those of the stock market. So adding one of these doesn’t lower the risk of the portfolio. Instead, it introduces a new dimension of risk, one that may be hard to assess.
a painful lesson
Portfolio managers who embraced beta in its infancy didn’t get this. They assumed uncorrelated= riskless, learned the hard way that this isn’t true when their supposedly defensive portfolios imploded due to sharply underperforming gold issues.
I’ve been looking at marketing materials for financial planning firms recently. Allocations to hedge funds are being touted with the idea that their returns are uncorrelated to those of stocks or bonds. This is substantially different from the original claims for this investment form. Over the past fifteen years or so, the hedge fund pitch has gone from being one of higher-than-market returns, to low-but-always-positive returns, to the present uncorrelated.
The reason is that in the aggregate hedge fund returns have consistently been lower than those for index funds for many years and that they do have years where their returns are negative. What’s left? …uncorrelated, just like zero-beta gold stocks. I guess it has been revived because the last “uncorrelated” investment disaster is so far in the past that few remember it.
why hedge funds?
Why have hedge funds at all in a managed portfolio? They must have some marketing appeal, sort of like tax shelter partnerships or huge fins on the back of a car, that are aimed at the ego–not the wallet–of the client. A darker reason is that the sponsoring organization may also run the funds, and would miss the huge fees they generate for their managers.
– What stocks to invest in